The use of an endless track as a traction enhancer for wheeled vehicles is well known. Typically, such belts comprise a plurality of individual track sections formed from a hard metal such as steel that are linked together for pivotal movement with respect to adjacent track sections. These track belts have traditionally been used to obtain better overall traction for the vehicle generally and in wet and slippery conditions particularly. Examples of such prior an track belts are disclosed in U.S. Pat. No. 3,497,271 to Keller, U.S. Pat. No. 4,089,565 to Loegering, et al., and U.S. Pat. No. 4,099,794 to Hoffart.
Generally, each of the track sections include a base pad structure having an elongated shape that engages the ground during operation of the vehicle. The base pad forms a cross bar that includes at least one cleat, and usually two, and that extends between a pair of opposed sidewalls, which in turn each extend generally upwardly from the base pad on opposite longitudinally spaced ends thereof. Adjacent track sections are linked together by a linkage mechanism. Usually, though not necessarily, the linkage mechanism includes the sidewalls having at least one clevis type structure that receives a link therebetween. In a double or dual pivot linkage such as that shown in the Keller '271 patent, the link extends between adjacent clevises of adjacent track sections. In the single pivot linkage, one end of the link is integral with the side wall of one of the track sections and extends into a pivotal engagement with the clevis of the adjacent track section. In both linkage mechanisms, the clevis and the link have aligned apertures that receive a fastener or pivot pin that forms therewith the pivotal link mechanism by which the adjacent track sections are connected. As noted, a double or dual pivot linkage mechanism includes a pair of clevis structures for each track section by which the track section is pivotally connected on both lateral sides to the adjacent track sections.
During operation of a vehicle utilizing such flexible belts, the vehicle tires are normally guided within the track sections by the side walls of the track section. The prior art track sections usually guide the tires by engaging the soft side wall of the tire. For example, both the Hoffart '794 and the Loegering '565 track sections each tend to guide the tire utilizing the tire side wall, resulting in side wall wear on the tire.
In addition, during normal operation, the vehicle will often experience forces directed sideways to the track belt, or along the longitudinal direction of extent of the individual track sections. When experiencing these side loading forces, the tires will tend to crawl upwardly along the sidewall of the track section. This side loading of the tires into the sidewall of the track section creates wear on the tire, in particular on the tire sidewall, which is usually thinner and softer than the tire tread and thus more susceptible to wear.
On uneven terrain, such as where rocks are encountered by one side of a track section, the track belt can experience significant rocking and flexing of the individual track sections relative to adjacent track sections or of an end of a single track section relative to the other end thereof. This rocking and flexing of the track sections also contributes to tire wear as well as significant wear on the linkage mechanism connecting adjacent track sections. In the single pivot linkage mechanism the pivot pin is forced to endure a significant weight transfer due to the rigidity of the linkage between adjacent track sections. That is, when an object is encountered by one side of the track section, the track section will tend to tilt. Since it is rigidly, and often integrally, attached at one end of the link, however, tilting of the track section is inhibited and the tilting load is transferred to the pin, which can cause significant, accelerated wear on the linkages of a single pivot linkage. The pin in effect acts as a saw, increasing the wear. Because the track sections of a double pivot linkage are pivotally attached at on both sides, the track section can pivot independently on one side of the pad with respect to the opposite side thereof, thereby lessening the load transfer to the pin, and thereby reducing the wear. As noted previously though, known double pivot linkages are relatively more flexible and therefore facilitate the tire wheels to walk out of the track belt.
The aforedescribed track belts are used frequently on vehicles in outdoor settings on earth or rock surfaces. Additionally, they are also finding increasing use on vehicles operating on artificial work surfaces such as concrete, asphalt, or like work surfaces. When used on such work surfaces, the cleats of the track sections will frequently damage the surface, particularly when used on skid-steer type of loaders, which tend to slide sideways on the track under certain operating conditions. Additionally, the engagement of the solid steel cleat with the concrete, asphalt or similar work surface can be noisy. Consequently, the use of the aforedescribed steel track belts has been limited primarily to non-concrete or similar work surfaces, that is, work surfaces where damage thereto is not a concern, and has thus reduced the market for these track belts in situations where they might otherwise find use.
It would be desirable to have an improved track belt formed of track sections that are cushioned to prevent or reduce damage to concrete or like surfaces and that reduce the noise associated with operating vehicles having such track belts on such surfaces.